import { type } from '@testing-library/user-event/dist/type'
import React, { Component } from 'react'

// 引入store, 用于获取redux中保存的状态。
import store from '../../redux/store'

// 引入actionCreator，专门用于创建action对象
import {createDecrementAction, createIncrementAction} from '../../redux/count_action'

export default class Count extends Component {
  /*   
    第一种方法：
    componentDidMount(){
    // 检测redux中的状态的变化。只要变化，就调用render
    store.subscribe(()=>{
      this.setState({})
    })
  } */

  increment = ()=> {
    const {value} = this.selectNumber
    store.dispatch(createIncrementAction(value*1))

  }

  decrement = ()=> {
    const {value} = this.selectNumber
    const count = store.getState()
    store.dispatch(createDecrementAction(value*1))
  }

  incrementIfOdd =()=> {
    const {value} = this.selectNumber
    const count = store.getState()
    if(count % 2 ===1) {
      store.dispatch(createIncrementAction(value*1))
    }
  }

  incrementAsync =()=>{
    const {value} = this.selectNumber
    const count = store.getState()
    setTimeout(()=>{
      store.dispatch(createIncrementAction(value*1))
    },500)
  }

  render() {
    return (
      <div>
        <h1>当前求和为:{store.getState()}</h1>
        <select ref={c=> this.selectNumber = c}>
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select>&nbsp;
        <button onClick={this.increment}>+</button>&nbsp;
        <button onClick={this.decrement}>-</button>&nbsp;
        <button onClick={this.incrementIfOdd}>当前求和为奇数时再加</button>&nbsp;
        <button onClick={this.incrementAsync}>异步加</button>
      </div>
    )
  }
}
